Nowadays, while traffic intensity is constantly increasing, also interest and discussions about different class passenger car and truck safety improvement possibilities become more and more significant. Despite the fact that both - cars and trucks daily use the same public roads, many essential requirements and safety systems are different. While working on passenger car body construction, equally much importance is given to both - active and passive safety systems. Basing on fact that lately light class passenger cars are becoming more and more popular in the world market, light class and heavy class passenger car passive safety requirements become even more important. As the main criteria for the improvement of passive safety is the necessity of common requirements for car force and shape compatibility, which would make possible to significantly improve performance of collision safety. The article deals with the necessary requirements and criteria, which have to be taken into account by passenger car and heavy truck manufacturers designing a new vehicle. There are also given theoretical calculation methods of collision kinetic energy, deformation energy, and other indicators. The article provides information on the car body design collision energy absorption capability, and on currently used superstructure construction materials. Nowadays one of the main barriers on the way to efficient vehicle collision analysis is the lack of common mathematical algorithm for deformation energy evaluation. The aim of my thesis is to work out such a mathematical algorithm, which would allow to calculate change of speed and loss of kinetic energy after collision basing on deformation analysis.